BIOGAS PLANT CALCULATIONBiogas plant

Zorg Biogas AG

Uetlibergstrasse, 132

CH-8045 Zürich, Schweiz

Tel. +41 44 5080081

Tel. +41 44 5080082

Tel. +41 44 5080083

E-mail: biogas@zorg-biogas.com

http://www.zorg-biogas.com

1

Content

1. Input data

2. Technical performances

3. Price

4. Terms and conditions

5. Working principles

6. Equipment description

2

23.08.2011

Input data for biogas plant calculation

ContactsProject name: Biogas plant

Contact person: Juan Soria Reategui

Position: Project mananger

Company: Municipal

Address: Plaza de Armas Yurimaguas - Peru

Telephone: 0051968481865

E-mail: juan7sori@hotmail.com

Input materials# Material name Quantity, ton/day Humidity, % Temperature, °С1. Food waste 15 50 25

2. Stomach content 1 70 25

3. Grass 3 70 20

4. Natural cattle manure 2 85 20

Output prefer:All biogas to electricity

3

Technical performancesof biogas plant

1. Biogas yield V, 5 235 m³/day

2. Number of reactors r, 2 pcs.,

3. Sum reactor volume V

r

, 4 800 m³

4. Solid bio-fertilizer output m

solid

, 9.1 ton/day

5. Liquid bio-fertilizer output m

liquid

, 5.7 ton/day

6. Area S, 0.8 ha

7. Electrical power consumed by biogas plant N

el.1

, 29 KW

8. Electrical power of co-generation unit, max N

el

., 526 KW

9. Produced electrical power N

el2

., 494 KW

10. Heat power consumed by biogas plant at -30 °C, N

heat1

, 234 KW

11. Heat power of co-generation unit, max N

thermo

, 545 KW

12. Produced heat power N

thermo2

, 289 KW

13. Staff, 1 people

Price list

Price EUR

Projectdocumentation Engineering * Equipment ** Construction ***

Biogas

plant

51 000 22 000 780 000 490 000

Co-generation unit - 10 000 540 000

* - travel expenses are not included;

** - delivery terms CPT Your destination;

*** - Construction can be done by Customer himself under Zorg Biogas's chief-montage.

ATTENTION: Equipment includes steel reactors

4

Contracts

Project implementation is executed simultaneously under several contracts: Engineering contract, Equipment supply contract, Construction supervision contract (Customer executes construction on his own with local

subcontractor).

Implementation terms

1 2 3 4 5 6 7 8 9 10

Project documentation

Equipment supply

CHP supply

Construction

Plant start-up

RE

SE

RV

E

Payment terms

1) Under project documentation development Contract:

50% down payment from the Contract price, 40% Contract price payment – after 2 months, Final 10% payment within 10 days after hand over act is signed.

2) Under equipment supply Contract: 30% down payment from the Contract price, 30 % Contract price payment – after 3 months, 30 % Contract price payment – after 5 months, 10% - upon readiness for shipment.

3) Under field supervision Contract: 50% down payment from the Contract price, 50% Contract price payment – in 4 months.

General contracting with prepayments and pro-forma act.

5

Biogas plant working principle

The technology of organic materials conversion is made by means of biochemical decomposition (hydrolysis) of high-molecular compounds into low-molecular organic compounds (organic acids, salts, and alcohols).Organic compounds + Н О→ С Н NО +HCO .2 5 7 2 3

Further conversion of obtained dissolved compounds like organic acids and alcohols (С Н NО , 5 7 2

HCO ) into gases - СН , СО . 3 4 2

С Н NО + HCO + Н О → СН + СО + NH .5 7 2 3 2 4 2 4

Biological process of consecutive (phasic) conversion of organic compounds can take place in anaerobic environment i.e. in oxygen-free tank (biological reactor). At the first stage of fermentation substrate hydrolysis take place under acidogenic bacteria influence. At second stage elementary organic compounds come through hydrolysis oxidation by means of heteroacidogenic bacteria with production of acetate, carbon dioxide and free hydrogen. The other part of organic compounds including acetate forms C1 compounds (elementary organic acids). Produced substances are the feed stock for methanogenic bacteria of third type. This stage flows in two processes of A and B type the character o which depends on caused by different bacteria type. These two types of bacteria convert the compound obtained during the first and second stages into methane CH , water H O and carbon dioxide CO .4 2 2

Methanogenic bacteria are more particular to living environment to be compared to acidogenic bacteria. They require complete anaerobic environment and need longer reproduction period. The speed and scale of anaerobic fermentation depend on bacteria metabolic activity.

That is why the biogas plant chemical process includes hydrolysis stage, oxidation, and methenization stage. For that kind of substrate these processes take place in the same reactor.

Biomass with quantity 60 tons per day and humidity 70% every day is transported to biogas plant area and discharged to preliminary tank. Biomass is loaded to preliminary tank by portions of 10-15 tons with interval 4-6 hours. The Biomass is mixed by two submersible mixers (agitators). For Biomass diluting in start-up period

3the water from pipeline in quantity 120 m per day is used. In operating period the filtrate after separator is used in the same quantity. Using of filtrate allows to reduce energy consumption for heating (because it is warm) and to return part of non digested organic dry matters back to technological process. In preliminary tank

0the substrate is heated up to temperature 20-25 C by heating manifold.

The prepared substrate is pumped to fermenters by substrate supply pump. In pumping pipeline the grinder is installed for crushing nonsolute parts of Biomass and other inclusions (straw, twigs, leaves etc). In pipelines the valves “M” are installed, which switche substrate flow and directs to each fermenter. The valves are

0controlled by automatic system. In fermenters the substrate is heated up to temperature 36-38 C. The heating system is installed in walls and bottom of fermenter, thus constant temperature sustains on whole digesting period.

Fermenter operating regime is mesophilous. The heated substrate in fermenter is mixed periodically (20-25 minutes in hour) by submersible agitators. The average time of digesting in fermenter is 26-30 days. Biogas

3goes up and gathers in gasholder. The volume of gasholder – 900 m . The weather protective film protects gasholder from atmospheric precipitation and damaging by foreign objects. The weather protective film is stand firmly because of air pressure from air blower.

To protect gasholder from overpressure the fermenter is equipped by safety valve, which starts working on pressure 5mbar and bleeds biogas to atmosphere. The sulphur is deluted from biogas by adding strictly definite quantity of air in fermenter.

6

Then biogas goes through gas pipeline to compressor, where the pressure is raised up to 80-100 mbar to satisfy the requirements of co-generator producer. Gas pipeline is equipped with condensate discharge unit. All the units work based on gauges limiting values.

After biogas enters to co-generation power plant, where it is burnt and output is electricity and heat. The heat from co-generator goes through heat exchanger for heating the biogas plant. Heating equipment is used for distributing the heat between biogas plant facilities.

The digested substrate from each fermenter goes to digested substrate tank and then by pump is pumped to separator where it is separated on solid and liquid biofertilizer. Solid biofertilizer discharged on the area and transported for storage, liquid filtrate is directed to filtrate tank from where part of it is returned back to

3technological process by pump in quantity of 120 m per day for diluting fresh Biomass and the rest part is pumped to lagoon by pump.

All technological process is controlled and operated by automatic system. Biogas plant work is visualized at central control room monitor. The control room is equipped with central control unit, which allows switch of any biogas plant module into automatic or manual mode with local or remote control.

7

Components

Substrate supply pump

Grinder (external view)

Grinder (internal view)

Pumping equipment and grinder

Pumps are used to transport substrate to the equipment and facilities in the biogas plant and away. Biogas plant design allows to access easily to all pumps. Pumps are driven by helical geared motor. Stator has hopper inlet for optimum filling of the pumping chamber, wear-protected, robust universal joint with feeding screw, robust bearing pedestal with close-coupled drive and self-centering of the drive shaft. Pumps have modular design for high flexibility, low life-cycle-costs.

Grinder is used for Pump protection from solid foreign obgects. It designed specifically for the efficient maceration, it is very effective in capturing irregular shaped objects. The layback cutter shafts are set at an angle to the incoming flow. If a rejection cycle is necessary, the object can drop into the built-in trash trap set clear of and below the cutter stacks, preventing damage. The trash trap is fitted with a large diameter access port to enable easy removal, cleaning and flushing.

The main advantages of grinder is following:

Mono ETOS cutters offer positive and effective solids maceration

Shafts operate at differential speeds to promote a tearing action on the solids

Pull back cutter stack allows removal without disturbing the pipeline

Cantilever shaft design eliminates the need for bottom bearings and seals, significantly reducing wearing components

Patented built-in trash trap with clean-out ports to catch any rejected material

Low cutter tip speeds, low power and low noise level

Each grinder is supplied with a programmable logic controller (PLC) to protect the machine against damage and overloads

8

Fermenter

Metallic fermenter with enamel coating

Insulating of metallic

fermenter

Ready insulated fermenter with decorative coating

Heat supply station

Heat supply station Heating manifold

Heating tubes inside fermenter

Fermenter is important part of biogas plant, It is made from steel sheet metal with enamel layer coating and set up on reinforced concrete foundation. An enamel layer protects the entire steel surface durably. It is glass-like and extremely resistant. Enameled fermenter is completely prefabricated from steel sheet segments. This fermenter is easy, fast, and safe to construct.The steel metallic fermenter has the following advantages: Steel panels are made according chess principle. Thus substrate inpermeability through metallic

overlapping is achived, fast changing of certain panels and possibility of expansion of fermenter; Enamel coating is layered be PUESTA method, it is dry powder and layered by electrostatic attraction. Thus the surface is uniform, very resistant and smooth; Screws made from stainless steel; All elements (flanges etc) are connected through EPDM membrane to protect enamel;To reduce heat consumption and to sustain certain temperature regime it is insulated. Outside it is covered with decorative coating.

Heating equipment is used for biogas plant heating and for sustaining constant temperature in fermenter. Heating equipment includes circulation pumps, heat exchanger, heating manifold, tubes. The heat supply source is co-generation power plant. The heat from co-generator contour is transferred to biogas plant contour by using heat exchanger, and then is pumped through contours of biogas plant by circulation pumps. Heat carrier is prepared water with additive of ethylene glycol.

0 0The inlet temperature in fermenter is 60 C, the outlet is 40 C.

9

Agitators (mixers)

The submersible motor agitator

The submersible motor agitator with guiding unit

3D Model

Leak proof motor drive with propeller

The submersible motor agitator with guiding unit

(view from inside the fermenter)

The submersible motor agitator serves for mixing renewable raw materials (RRM), liquid Corn (maize) silage and similar substrates. The electro-motor driven submersible agitator is designed for submersion operations in potentially explosive environments of Ex zone 2 and complies with Directive 94/9 EC. The submersible agitator can be attached to most sliding masts by means of the motor support. A mounting option for a hauling cable is provided on the motor support for height adjustment purposes.

Due to the 4-roller guidance of the motor support, the agitator can be lifted and lowered without friction and the square mast, even if the pull of the hauling cable is slightly angular. The motor support is designed for a 100 x 100 mm square sliding mast as standard, but can also be used for an 80 x 80 mm sliding mast by changing the rollers. The strain relief of the connecting cable can be positioned in the extension of the motor or towards the top on the motor support, depending on the requirements. This enables universal utilization with the most various installation kits.

The geared motor is made of spheroidal graphite iron(GGG40) and painted, the propeller is galvanized and the motor support is made of stainless steel. Thesubmersible motor agitator is designed as a water pressure-tight monoblock unit for driving the

three-vane propeller. The submersible agitator is of modular design, submersible electro-motor with flange-mounted planetary gear and bearing flange for holding the propeller. The conical shaft in the bearing flange is mounted in the oil bath by two angular roller bearings and sealed off from the agitating substrate with a mechanical seal.

10

Co-generation Power plant

Co-generation Power Plant in

container (external view) Co-generation Power Plant

installed on biogas plant

Co-generation Power plant (CHP) is used for producing electricity and heat. CHP is a very efficient technology for generating electricity and heat together. A CHP plant is an installation where there is simultaneous generation of usable electric power and heat in a single process. CHP can provide a secure and highly efficient method of generating electricity and heat at the point of use. Due to the utilization of heat from electricity generation and the avoidance of transmission losses because electricity is generated on site, CHP typically achieves a 35 per cent reduction in primary energy usage compared with power stations and heat only boilers. This allows for economic savings where there is a suitable balance between the heat and power loads.

Another important factor that witness for benefits of cogeneration and CHP is its highenvironmental purity. CHP have lower ranges of pollutant emissions and allow toreducing heat pollution of atmosphere. The current mix of CHP installations achieves areduction of over 10 per cent in CO2 emissions in comparison with gas fired combined cycle gas turbines.

11

Gasholder

Gasholder with weather protection film, installed on fermenter

Gasholder serves for biogas storage and for making even pressure and biogas composition. Gasholder system has two layer construction. External - weather protection film PVC-coated polyester fabrics, UV-protected, both side with finisher, 3.000 N/5cm, internal membrane PELD (gasholder) - methane permeation max. 260 cm3/m2 * d * 1 bar, 650 N/5cm biogas resistant, Gasholder film cold resistance – 30°C. Internal film is stretched under produced biogas pressure. The air is blow into space between external and internal membranes for making pressure for internal membrane and making form for external. The biogas pressure in gasholder is 2 – 5 mbar.

Membranes are designed and cut out on NC machines. Welding is executed by high frequency currents. All these makes big advantages as for quality andservice live comparing to hand made membranes and welded by temperature equipment. Gasholder is fastened to wall by pneumatic lock. It makes junction very strength and gas proof. Pneumatic lock comprises: trapeziodal profile, anchoring, compressor for making pressure in pneumatic lock, tube for locking gasholder in profile. In order to prevent damaging of gasholder because of over pressure the savety valve is installed.

To survey internal membrane the acrylic inspection window is installed into external membrane. From gasholder the biogas goes through gas pipeline to co-generation power plant, where electricity and heat is produced.

12

Separator

Separator

Control cabinet (internal view)

Automatics and electric equipment.

Control panel Technological process visualization

The Separator separates water from solids. It operates continuously and automatically according to the press screw separator principle and separates thin and viscous compounds. The solid matter / liquid compound is pumped from the inlet chamber by the press screw into the horizontal screen. Some of the water flows due to the force of gravity through the screen. The press screw conveys the rest of the water with solid particles (also smallest particles) into the press zone in the last section of the screen. Here a permanent regenerative, compact solid matter is generated and is then pressed out through the outlet of the machine, which can be easily filled into containers. The separated fluid slows through the outlet underneath the machine. On the grounds of narrow tolerance the inside of the screen is permanently kept clean.

Process control equipment is used for the supervision and regulation of the operation of the plant and for the limitation of damage. In case of emergency, for example, breakdown of the electrical powersupply, the biogas plant is automatically transferred to safe operating conditions by the process instrumentation. Necessary electrically driven devices are supplied with emergency power. Automatic system allows to supervise the plant parameters in real time and to recognize and correct aberrations immediately; to run the plant on its optimumand thereby to save resources and costs; to make recordings for the electronic journal of operation parameters. Automatic system consists of control cabinet, sensors for parameter control of technological process and execution devices. Control cabinet is designed on the basis of industrial controller Siemens CPU315-DP2 with using periphery distributing system Simatic ET200S and operator panel OP277 Touch with touch-sensitive control. Communications is executed by PROFIBUS and MPI with physical interface RS-485. Control program is designed on base Simatic Step7. Control cabinet is modular design. Upper part has power box, central and front-end processor. Below periphery distributing system Simatic ET200S is installed with input – output unit. In lower part the interface relay and clips are installed for connecting execution devices. All plant is operated by 1 operator.

13